When in vitro fertilization ends unsuccessfully... What are the causes? (Part one)

The first question a patient will ask if they receive a negative test after an In Vitro Fertilization (IVF) procedure is "Why did my IVF cycle fail?" A failed IVF cycle is a very delicate and very difficult moment for the patient… It is painful because all the hopes that the patient builds and nourishes during this in vitro fertilization cycle vanish immediately… The emotional stress is added to the not small financial bill that for the patient goes within 2-3 weeks

Human nature itself aims to find the right answer after every failure in order to avoid it in the next attempt. However, this does not happen in In Vitro Fertilization… Unfortunately, doctors are not able (and this because such are the levels of knowledge everywhere in the world) to give a reason for the failure of in vitro fertilization in some cases.

• You as a patient may have a perfect in vitro fertilization cycle – many eggs, very good fertilization, very good quality embryos, a very good endometrium, a very easy transfer of embryos into the uterus – and unfortunately a negative result after two weeks…
• On the other hand, your friend may have an in vitro fertilization cycle not as good as yours (with fewer eggs and with lower quality embryos) and end up with a positive pregnancy test result after 2 weeks.

IVF is, in a perspective, also a "game of chance" which involves not only your financial resources but also your dreams of becoming a mother. It is very sad that there is still no explanation for every IVF case, whether it ends successfully or with a negative result.

This is explained by the fact that our level of knowledge is not enough to explain the biological process that controls the development of the embryo and its implantation. With the transfer of the embryo into the uterus, no one is able to know and predict what will happen with it afterwards. Indeed, how can we "track" the path/fate of a bunch of cells (the embryo) when they are in the uterine cavity? We are not able to predict which embryo will implant and why, and therefore we cannot know why an in vitro fertilization cycle ends successfully or fails!

Unfortunately or fortunately, no one asks the other quite logical question – "Why did my IVF cycle succeed?" – This question still has no answer either!

The first person to whom the patient turns in these cases are the doctors who carried out the in vitro fertilization process (gynecologists and embryologists). They have determined the indication for In Vitro Fertilization and they have told you that you have concrete chances of success. The patient's expectation is that the doctor has an answer to the question – "Why did my IVF cycle fail when the progress was good?"

Some patients go as far as to doubt the competence of the clinic, laboratory or even the doctor who performed the procedure. Some patients, on the other hand, blame themselves thinking that their body does not function properly and is not capable of holding (but rejects) the embryos created with laboratory effort. Some blame themselves because of the poor diet they have maintained or due to fatigue or neglect during the two weeks following the embryo transfer.

However, a patient who has listened carefully to what the doctor has explained before the procedure (and not what she wants to believe or what she has heard from her friends) or has read even a little about in vitro fertilization understands very well that a failure in in vitro fertilization is not the "fault" of the doctors nor the patient. Such patients bear a negative result better and find it easier to move on towards a reevaluation of the case and another IVF attempt.

The most important task of a doctor is to prepare patients also for a negative result at the end of in vitro fertilization. A good IVF specialist will spend time and energy explaining to the patient the uncertain points of IVF and the different chances that different couples may have. This is because some of the patients wrongly believe that "now that they started in vitro fertilization after 9 months they will have a baby". No doctor and no clinic promise this.

A doctor who spends time from the first moments explaining the chances (which might seem less than your expectations) believe me, is more prepared than those doctors who spend only 30 seconds with you promising certain success.

Why does in vitro fertilization fail?

As we have already mentioned above, the reasons are not known for sure. We can summarize the following possibilities:

• Poor quality of embryos
• Non-receptive uterus (womb)

Let's take a hypothetical case: a fertile couple that is trying to start a pregnancy in their bedroom. Does every sexual intercourse of this couple during the woman's fertile days (middle of the cycle) result in a pregnancy? Of course not! A fertile couple may need a whole year to achieve pregnancy. The chances of this fertile couple to achieve pregnancy during a menstrual cycle are 15 – 25%. These figures clearly show that human reproduction is not a perfect process! Which means that not every menstrual cycle is perfect and that not every menstrual cycle results in the production of a "normal" egg.

Once we accept that the yield of natural reproduction in humans is 15 – 25% then we cannot claim 100% success rate in in vitro fertilization. In an IVF cycle, the chances of having a pregnancy vary from 40-50%. However, we are unable to determine with certainty whether it is the quality of the embryos or the reduced receptivity of the uterus that stands behind an IVF with a negative result.

What does not cause "failure" of the in vitro fertilization cycle:

• Lack of lying down.
• Cough
• Stress
• Diet
• Pseudoscientific reasons such as NK cells or HLA mismatch.